Shroyer
venturi loading system



1970 H. F. SHROYER VENTURI LOADING SYSTEM Original Filed Aug. 22. 1967 2Sheets-S11E91; 1

INVEN1OR HAROLD F SHROYER BY aw! IJW ATTORNEY Oct. 6, 1970 SHROYER Re.26,962

VERTURI LOADING SYSTEM Original Filed Aug. 22. 1967 2 Sheets-Sheet aFIG. 2

l2 E E l ZEI P ER INVENTOR HAROLD F SHROYER United States Patent OfliceRe. 26,962 Reissued Oct. 6, 1970 Int. Cl. B65g 53/10 US. Cl. 30227 6Claims Matter enclosed in heavy brackets appears in the original patentbut forms no part of this reissue specification; matter printed initalics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE An apparatus for feeding polymeric beads intoa board forming apparatus. It consists of a venturi chamher withdirectional air inlet nozzles and has a rectangular discharge endadapted to fit into the forming apparatus.

This invention relates to filling devices for continuous moldingmachines. In one particular aspect it relates to an air actuated fillingdevice.

It is known to prepare foamed polymeric boards or sheets by the use ofendless belts arranged to form an open ended molding space. Thepolymeric materials usually in the form of beads are fed into the spacebetween the belts and steam is applied expanding the beads into therectangular shape of the molding space.

One of the problems in the use of this molding tech nique is in thefeeding of polymeric beads into the belt formed cavity. The beads mustbe uniformly distributed through the cavity to provide a uniform voidfree product. The conventional screw feed devices are deficient in thatthey tend to compress and compact the beads prior to feeding thembetween the belts.

It is therefore an object of this invention to provide a novel fillingdevice whereby expandable polymeric beads are continuously fed into abelt forming cavity in a uniform manner without prior compression orcompaction of the beads.

This and other objects of the invention will become apparent from thedetailed description and drawings wherein:

FIG. 1 is an isometric front view of the feed apparatus of thisinvention;

FIG. 2 is an isometric rear view of the feed apparatus v of FIG. 1;

FIG. 3 is a sectional view of the apparatus of FIG. 1 through 3-3.

FIGS. 1 and 2 illustrate 4 feed conduits 14, 15, 16 and 17, which areunitized into feed apparatus 10. Con duits 14, 16, 17 and 18 areidentical and a description of one is sufiicient for an understanding,however, though 4 conduits are illustrated, this is not limitation onthe invention. A feed conduit may be used by itself or in combinationwith others depending upon the width of the cavity formed by the beltsin the board forming apparatus.

Conduit 14 is open ended and is cylindrical at the feed entrance end andrectangular at the feed discharge end. The rectangular shape of thedischarge end allows the feed apparatus to be inserted in therectangular area 13 between belts 12-12 of the board forming apparatus.

Though the feed entrance end of conduit 14 is illus trated as beingcylindrical, it is understood that it may be square or rectangular,without departing from the scope of the invention.

FIG. 3 illustrates feed conduit 14. It consists of a venturi chamber 19and directed inlet nozzles 21. 22 and 23 (nozzles 21 and 22 only areshown in FIG. 3). The three nozzles and their relative locations in eachof the conduits 14, 16, 17 and 18 give the desired dispersion of thepolystyrene beads across the rectangular discharge end of each conduitof the feed apparatus 10.

The single nozzle 21 (in conduit 14) has the highest air velocity of thethree nozzles and creates the initial suction to draw the polystyrenebeads into the conduit 14. Nozzle 21 is located immediately anterior tothe entrance end of the conduit 14. Nozzles 22 and 23 control thedispersion of the beads across the rectangular dis charge end of conduit14. They are located side by side approximately at the point where theventuri chamber 19 tapers from a cylinder to a rectangle.

In operation air flow from nozzles 21, 22 and 23 sucks beads 11 from asuitable container (not shown) into the venturi chamber 19 wherein theyare dispersed and ejected into the board forming cavity 13 between belts12-12.

In an embodiment of this invention plastic shields 24 and 26 areattached to the upper and lower surfaces respectively of the dischargeend of conduits 14, 16, 17 and 18 to reduce the wear on the belts 14-14.

The novel feed apparatus of this invention is particularly useful whenslats are used for the belts 12-12. When using a slat belt, thepolystyrene beads have to be delivered beyond the open slat area, to thepoint where the slats are closed. Otherwise the beads enter between theslats creating a bead loss and Wedge the slats further apart, stretchingthe belt. The high kinetic energy imparted to the beads by the air flowin the venturi chamber 19 carried the beads well into the closed slatarea of the belt cavity 13.

An additional advantage of the novel feed operation is that the air flowfrom the venturi chamber 19 reduces the chances of the steam used inmolding from entering the feed hopper and welding the polymeric beads enmasse. A further advantage is the ease with which feed rate can becoordinated with belt speed.

What is claimed is:

1. In an apparatus for making coherent bodies from expandable granulesof thermoplastic material compris ing a channel defined by a pluralityof movable endless belts, means for charging said channel with saidexpandable polymeric material, said charging means having [a pluralityof conduits] at least one conduit leading into the entrance end of saidchannel, [each of] said [conduits] conduit containing as an integralpart thereof an open end venturi chamber having an entrance end and arectangular discharge end, a plurality of directional inlet nozzles insaid venturi chamber for the passage of air under pressure into saidchamber, whereby said air under pressure passing through said venturechamber sucks said polymeric material into said entrance end and ejectssaid material and air from said discharge end at high velocity into saidbelt formed channel.

2. The apparatus according to claim 1 wherein a plastic sheet isafiixedly attached to the upper and lower surfaces of said dischargeends of said conduits to prevent said conduits from engaging said belts.

3. In an apparatus for making coherent bodies from expandable granulesof thermoplastic material comprising a channel defined by a plurality ofmovable endless belts, means for charging said channel with saidexpandable polymeric material, said charging means having [a pluralityof conduits] at least one conduit leading into the entrance end of saidchannel, [each of] said [conduits] conduit containing as an integralpart thereof an open ended venturi chamber having a cylindrical entranceend and a rectangular discharge end, a first directional inlet nozzleanterior to said entrance end for the passage of air under pressure intosaid chamber, second and third directional inlet nozzles for the passageof air under pressure into said chamber, said second and third nozzlebeing side by side at the tapering of said [cyclindrical] cylindricalentrance end into said rectangular discharge end, whereby said air underpressure passing through said venturi chamber sucks said polymericmaterial into said entrance end and ejects said material and air fromsaid discharge end at high velocity into said belt formed channel.

4. The apparatus according to claim 2 wherein a plastic sheet isafiixedly attached to the upper and lower surfaces of said dischargeends of said conduits to prevent said conduits from engaging said belts.

5. The apparatus of claim I wherein said charging means has a pluralityof said conduits leading into the entrance end of said channel.

6. The apparatus of claim 3 wherein said charging means has a pluralityof said conduits leading into the entrance end of said channel.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS ANDRES H. NIELSEN, Primary Examiner US. Cl. X.R.264-51; 18-4

